This invention relates to a gastrointestinal aspirating device with suction breakers and a method of use in treating patients.
Post-operatively, gastrointestinal functions usually deteriorate. The causes of this deterioration are varied and include such factors as the use of anesthesia or pain killing drugs, and the handling of the bowel during the operation. Additionally, air swallowed by the patient contributes to gastrointestinal malfunctions since the gas is inefficiently propelled through the digestive tract. This causes a problem commonly known as abdominal distention which not only impairs bowel function and interferes with the rate of absorption of nutrients through the bowel, but often prevents the patient from breathing deeply or coughing, which can lead to severe pulmonary difficulties. In severe cases, the pressure caused by the abdominal distention has been known to break open the patient's wound. One of the indirect effects of abdominal distention is the fact that due to the pain associated with it, and the lesser rate of bowel absorption, the patient often becomes undernourished which slows the healing process. It has, therefore, been a long-standing objective of the medical profession to prevent abdominal distention while providing sufficient nutrition in order to speed the patient's recovery.
In order to meet this need, a large variety of aspirating tubes have been developed. A significant number of these tubes also include feeding means such as disclosed in my patent application, Ser. No. 312,215 filed 10-19-81/CIP Ser. No. 585,632 filed 3-8-84, the disclosure of which is incorporated by reference into this patent application. While all of these devices are effective to varying degrees, there is one main difficulty which virtually all these inventions have encountered and none have yet effectively been able to solve. This problem stems from the fact that most of these tubes when placed within the patient, are in contact with or in the area of various pliable membranes which have a tendency to be drawn into the aspirating orifices when suction is applied through the tubes. Thus, the aspirating ability of the tube decreases in direct proportion with the number of orifices which are blocked.
Aspirating orifices may also become blocked or plugged by the material which is to be aspirated. However, this type of blocking or plugging can generally be avoided by utilizing orifices which are sufficiently large in area to meet the expected flow. In order to obtain maximum flow through these orifices, their area is equal to the cross-sectional area of the lumen within the tube. Any increase in the area of the orifices beyond this cross-sectional area would yield no beneficial result since the area of the lumen would then simply act as the flow limiting factor. Thus, one generally chooses a tube having a diameter which is appropriate for the patient being administered to and this limit often sets the parameters for the size of the lumen and the associated aspirating orifices.
While these larger orifices are needed in order to assure desirable flow rates without plugging by the materials to be aspirated, due to their area, they form a strong bond when they attach to an organ's inner lining. Once one of the orifices attach to the organ wall, greater suction develops through the other orifices. This increase in suction causes other orifices to be drawn to the inner walls and also become occluded which, again, increases the suction applied to the remaining orifices. Thus, with those inventions heretofore known, a chain reaction occurs which results in the blocking of virtually all the aspirating orifices.
In order to disengage the aspirating orifices from the inner walls, it was often necessary to stop the suction until the tube had broken free. While this would normally enable the normal movements of the body and organs to eventually disengage the tube, there are two major drawbacks which render this procedure undesirable. First, and most important, is the fact that during the time that the suction is not being applied, noxious materials within the patient's body may be propelled beyond the range of the tube, and therefore, be unrecoverable once the suction is reinstituted. Secondly, the input of time which is necessary in order to monitor and disengage the tube as needed can become substantial. Thus, time which could be utilized more effectively is spent trying to maintain the tube at an acceptable level of operation.
In order to overcome this difficulty, some tubes have been designed with aspirating orifices placed at different locations circumferentially around the tube. Although this arrangement has helped to lessen this difficulty in some situations, it is still common, primarily due to the strong adjesive powers of the large orifices to have an unacceptable number of these orifices blocked.
In my feeding and aspirating tube which has been incorporated by reference above, there is an aspirating orifice in the proximal segment of the small bowel and a feeding orifice downstream from the aspirating orifice. Since the proximal segment of the small bowel is a small diameter conduit, this aspirating orifice effectively removes most of the matter entering from the stomach. In addition, this aspirating orifice also serves to withdraw any food which, administered through the feeding orifice, backs up due to overfeeding. Due to the important functions of this aspirating orifice, it is obviously essential that any clogging or blocking of this orifice be avoided.
For these reasons, I began looking for different ways to either prevent these aspirating orifices from attaching to the wall lining or provide a way to automatically disengage them once they had attached. As indicated by the procedure wherein the suction is completely eliminated, a reduction of the suction created a situation wherein the natural movement of the wall lining and the tube was sufficient to disengage the aspirating orifice. However, while I wished to reduce the holding force through these orifices sufficiently to allow them to disengage, I also wanted to maintain aspiration to prevent noxious materials from passing beyond the range of the tube. After much deliberation, I began experimenting with a secondary set of orifices, the main purpose of which would be to reduce the level of suction within the lumen when the primary orifices were occluded by the wall lining. When the aspirating orifices are occluded, the gas and liquid inflow through the secondary orifices causes a marked decrease in the level of suction within the aspirating lumen. This reduced suction within the lumen is sufficient to allow the larger aspriating orifices to break free from the wall lining. If the smaller orifices become attached, they are easily disengaged by the normal movement of the lining and tube since the reduced area of these smaller orifices results in less holding power to the wall lining. These suction breaker orifices had to be large enough to provide a sufficient drop in suction yet small enough that the holding power against the wall linings was ineffectual. My preferred size range for these orifices was from 1/3 to 1/20 of the surface area of the larger aspirating orifices, or the cross-sectional area of the aspirating lumen which should be equal.
It is, therefore, an object of this invention to provide an aspirating device which is effective in avoiding abdominal distention without frequent monitoring.
It is also an object of this invention to provide as aspirating device which is less subject to being occluded than prior devices.
It is yet another object of this invention to provide a feeding and aspirating device which prevents overfeeding through the use of these improved aspirating means.
Briefly described, the preferred embodiment of this invention consists of a tube having a feeding lumen and as aspirating lumen which are inserted into the patient's body and secured thereto. Both the aspirating lumen and the feeding lumen have orifices so as to communicate with various sites within the patient's body. There are two sets of aspirating orifices. One set of primary orifices act as main aspirating sites, while the secondary set of orifices act as suction breakers for the primary aspirating orifices. At predetermined points along the tube, there are placed a pair of orifices, one primary and one secondary orifice. When in its secured position, the feeding orifice is positioned in the proximal segment of the small bowel. Upstream from the feeding orifice, and before the pyloric sphincter, at least one primary and one secondary orifice communicates with the proximal segment of the small bowel. In the stomach, the same aspirating lumen has orifice pairs for aspirating the stomach.